Validation of a new formula for calculating the energy requirements of burn patients

Abstract

In a previous study, we analyzed the roles of the estimated basal energy expenditure (EBEE) calculated by the Harris-Benedict equation, caloric intake (CI), total burn surface area (TBSA), body temperature (Temp) and number of post-burn days (PBD) in order to estimate the resting energy expenditure (EE) of burn patients. By multiple regression analysis we found that the measured EE (MEE) is best approximated by the following formula: -4343 + (10.5 x %TBSA) + (0.23 x CI) + (0.84 x EBEE) + (114 x Temp (degree C)) - (4.5 x PBD), r = 0.82, p less than 0.001, (Toronto formula (TF)). To validate this, 10 patients with a mean TBSA of 49.1 +/- 5.5% had their resting MEE done by indirect calorimetry when fed either by the TF or by 2 x EBEE. The caloric intake when on 2 x EBEE was 3260 +/- 45 kcal/day which significantly exceeded the MEE (2765 +/- 101 kcal/day, p less than 0.001). The caloric intake when on the TF was 2542 +/- 52 kcal/day and matches the MEE which was 2537 +/- 86 kcal/day (NS). These results show that the TF matches the MEE very closely. With the addition of a factor of activity for the 24-hr EE, it can be used to accurately feed individual burn patients.